1. Field of the Invention
The present invention relates to safety-locks for multi-position windows. More particularly, the present invention relates to safety-locks for multi-position windows which prevent the window from pivoting about a vertical axis until the safety-lock is in the unlocked position.
2. Description of the Prior Art
There are many designs for security locks for multi-position windows or French windows. One lock design has a housing externally mounted on the lower horizontal portion of the moveable sash frame at the end that is distal from the vertical hinge axis and a catch externally mounted on the vertical portion of the stationary frame adjacent the housing. The housing contains a key operated bolt which slides along a horizontal axis normal to the horizontal portion of the sash frame. In the locked position, the bolt extends into an opening in the catch. In the unlocked position, the bolt is slid out of the opening within the catch.
In the locked position, the bolt in the opening prevents the sash from rotating about the vertical axis out of the stationary window frame. In order to be able to rotate the window sash about the vertical axis, the lock must be unlocked. Further, in order to be able to rotate the window sash about the horizontal axis, the lock must be placed at the sash horizontal axis. If the lock is placed in any other location along the sash frame, the lock must be unlocked in order to rotate the window sash about either the vertical axis or horizontal axis.
U.S. Pat. No. 3,911,621 describes a tilt and turn window having a drive train around three sides of the sash. The drive train is moved linearly by a three-position handle. Movement of the drive train switches the sash from a lockdown position in the window frame, to a position enabling rotation of the window frame on a vertical axis and finally, to a position enabling rotation out of the window frame on a horizontal axis.
When the handle is moved upwardly from center position the drive train is moved counterclockwise, thereby setting the window sash for rotation out of the window frame on the horizontal axis. When the handle is moved downward from the center position, the drive train moves clockwise setting the window sash for rotation out of the window frame on the vertical axis.
A key operated lock mechanism having a finger that is rotated by the key is installed just past the clockwise end of the drive train and positioned such that the finger can be turned to a position so as to interfere with the movement of the drive train, thereby preventing placement of the handle in a position which allows rotation of the window sash on the vertical axis. To allow placement of the handle into a position which allows rotation of the window sash about the vertical axis, the key must first be inserted into the lock, and then the finger must be turned to a position where it will not interfere with the movement of the drive train.
There are many drawbacks to this locking arrangement. First, a separate key is required to turn the lock from the locked position to the unlocked position. If one were to misplace the key, the lock would not be usable. Further, since the lock does not normally assume the locked position, then it can be kept in the unlocked position at all times, thereby defeating the purpose of having a lock altogether.
U.S. Pat. No. 4,074,462 describes a tilt and turn window having a drive train similar to the one described in his U.S. Pat. No. 3,911,621. A key operated lock mechanism is mounted on the frame of the sash. The lock includes a latch which extends into a longitudinal slot located in the drive train so that one end of the slot urges against the latch and prevents movement of the drive train into a position which will allow the sash to rotate out of the window frame on the vertical axis. Rotation of the latch out of the longitudinal slot with the key permits the drive train to move into position which will allow the sash to rot out of the window on the vertical axis.
The drawbacks to this locking arrangement are similar to that of U.S. Pat. No. 3,911,621. Namely, a separate key is required to turn the lock from the locked position to the unlocked position, and if one were to misplace that key, the lock would not be usable. Additionally, since the lock does not normally assume the locked position, it can be kept in the unlocked position at all times, thereby defeating the purpose of having a lock altogether.
U.S. Pat. No. 5,881,498 describes a multi-position window having a locking mechanism which allows rotation of the sash out of the window about the horizontal axis and prevents rotation of the sash about the vertical axis until the lock is in the unlocked position. The locking mechanism includes a bolt and a strike configured to receive the bolt. The locking mechanism further includes a hole in the sash frame which aligns with the bolt and the strike when the drive train is in a position which enables the sash to rotate about the vertical axis. The sash, even though in position to rotate about the vertical axis, cannot rotate about that axis until the lock is unlocked. In order to unlock the locking mechanism, a key is inserted into the hole in the sash. The key moves the bolt out of engagement with the strike, and thereby allows the window to rotate about the vertical axis. Similar to the previous locking mechanisms, a key is required to unlock the sash. If this key were misplaced, one would not be able to open the window.
One object of the present invention is to provide a safety-lock for a multi-position window which remains in the locked position so as to prevent rotation about the vertical axis while not interfering with the pivoting of the sash about the horizontal axis.
Another object of the present invention is to provide a safety-lock for a multi-position window which does not require a key for operation of the lock.
Another object of the present invention is to provide safety-lock for a multi-position window which will automatically be placed in the locked position when the sash is returned into the stationary window frame after rotation about the vertical axis.
Other objects and advantages of the present invention will be apparent from the following description of the invention.
In accordance with the present invention, a safety-lock mechanism for use with a multi-position window having a stationary window frame, a sash window frame positioned within the stationary window frame and selectively pivotable out of the stationary window frame about a vertical axis and a horizontal axis, and a drive train positioned between the sash window frame and the stationary window frame, the drive train being moveable between at least a first position which enables the sash window frame to be pivoted about the horizontal axis and a second position which enables the sash window frame to be pivoted about the vertical axis. The safety-lock mechanism includes a spring-biased pin provided on the sash window frame. The pin has a proximal end, a distal end, a locked position and an unlocked position, and is normally biased in the locked position. An aperture is provided within the drive train and is configured to receive the proximal end of the pin. In the locked position, the proximal end of the pin extends into the aperture so as to prevent movement of the drive train from the first position into the second position. When the pin is placed in the unlocked position, the drive train is capable of being moved from the first position into the second position, thereby allowing the sash window frame to be pivoted about the vertical axis.